Heater



FIG. 1 is a perspective view of the heater design;

FIG. 2 is a left side elevation view of the design shown in FIG. 1;

FIG. 3 is a right side elevation view of the design shown in FIG. 1;

FIG. 4 is a top plan view of the design shown in FIG. 1;

FIG. 5 is a bottom plan view of the design shown in FIG. 1;

FIG. 6 is a front elevation view of the design shown in FIG. 1; and,

FIG. 7 is a rear elevation view of the design shown in FIG. 1.

The broken lines shown in the views depict environmental subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a heater, as shown and described. 